TABLE 2.

Published studies examining the relationship between Ureaplasma spp. and male infertility

Authors (yr)	Reference	Country of study	Patient group	Sample type	No. of participants	Method of identification	Species differentiated	Key findings relating to Ureaplasma spp.
Huang et al. (2016)	57	China	Men attending a reproductive center	Semen	19,098 infertile men and 3,368 fertile men	Culture	No	Ureaplasma spp. were significantly associated with infertility.
								Ureaplasma spp. were significantly associated with reduced motility and normal forms in infertile men compared with fertile controls.
Huang et al. (2015)	56	Multiple countries	Meta-analysis	NAa	611 infertile men and 506 fertile men	NA	Yes	U. urealyticum was significantly associated with infertility.
								U. parvum was not associated with infertility.
Zhang et al. (2014)	54	China	Men attending an infertility clinic	Semen	223 infertile men and 146 fertile men	Culture	Yes	U. urealyticum was significantly associated with infertility compared with U. parvum.
								Semen positive for U. urealyticum showed a decreased concentration of spermatozoa and decreased motility.
Abusarah et al. (2013)	55	Jordan	Men attending a urology clinic	Semen and first-void urine	93 infertile men and 70 fertile men	PCR	Yes	Ureaplasmas were found more frequently among samples from infertile men (10.8%) than among those from fertile men (5.7%).
Zeighami et al. (2009)	53	Iran	Men attending an infertility center	Semen	100 infertile men and 100 fertile controls	PCR	Yes	Ureaplasmas were detected significantly more often in semen from infertile men than in semen from controls.
								U. urealyticum was detected in 9% of infertile men vs 1% of control men.
								U. parvum was detected in 3% of infertile men vs 2% of control men.

^aNA, not applicable.